36 Plymouth cooling system on 52 Dodge motor?

[n1gzd_plymouth]

I am pretty sure that I have the 36 Plymouth cooling system components on my 52 Dodge motor (36 Plymouth that has 320 CI Dodge truck block but accessories of original 36 Plymouth engine).

I am pretty sure I understand why my new water pump looks slightly different than the orignal one (see pictures below). You can see from my pictures which cooling system I have. In the pictures of my new water pump you can see where my bipass neck connects there is a round threaded hole instead of the square hole on my original pump.

1) Is this because in some applications there is just a pipe threaded on there instead of a bolted neck (but this is a general purpose pump). The new one came with a plug that i can use to cap off the heat (my old pump did not have support for heat I don't think).

2) What is the best sealant to use. I seem to have just about every kind of sealant in my shop but I never am quite sure which one to use. I have some blue rtv that indicates that it is good for cooling components. Is this what you recommend? It seems like it could be hard to get this water pump to block surfaces to be water tight (compared to how the pump installed on my Buick straight 8 anyway). See second message for rest of pics (exceeded max for this message)

Rebecca

[n1gzd_plymouth]

A few more shots:

[Young Ed]

You are correct that the new pump you have is multi purpose. When they went to internal bypass the top of the water pump just got a threaded elbow into it for a heater hose connection. You are wrong though that your old pump didn't support a heater. The pump did but the bypass piece that you have bolted on top didnt. You would have had to switch to one like in this picture. As you can see I had my heat blocked off at first too

[Don Coatney]

As Ed mentioned you have an external by-pass system. NAPA now sells the correct thermostat (#155) for your engine. Assembly as shown below. this is a 180 degree thermostat. I used grease only on my gaskets when I installed my water pump. Also use plumbers teflon tape on the threaded portion of the bolts that attach your water pump as these bolts penetrate the water jacket.

[martybose]

The other thing you should be aware of is that your new pump has the extra hole in the backing plate for the internal bypass used on the 50's and up motors. It should be sealed up against the head when it is bolted on, but you might want to see if the backing plate from your old pump could be substituted just to be sure.

Marty

[n1gzd_plymouth]

As Ed mentioned you have an external by-pass system. NAPA now sells the correct thermostat (#155) for your engine. Assembly as shown below. this is a 180 degree thermostat. I used grease only on my gaskets when I installed my water pump. Also use plumbers teflon tape on the threaded portion of the bolts that attach your water pump as these bolts penetrate the water jacket.

That thermostat does not look anything like mine. I will post a picture tonight. Also, I don't think that mine uses a gasket.

I will post pics of what I have tonight.

Rebecca

[n1gzd_plymouth]

my thermostat looks like the one pictured on this page:

http://www.oldmoparts.com/j.htm

Rebecca

[Don Coatney]

A gasket is required. The #155 thermostat replaces the one pictured below.

[n1gzd_plymouth]

A gasket is required. The #155 thermostat replaces the one pictured below.

Do you like the NAPA one better than the old style one. On my Buick I had to drill a vent hole in the one from NAPA because it was missing.

I will check to see if I got a gasket. On the phone they told me that on the older engines it was not needed but hopefully they sent it anyway.

Thanks.

I hope that I can get paint to stick to my new pump. Other pumps that i have bought in the past had primer on them. This one seems to have a light machine oil residue on it that I will need to get off with a solvent before painting.

Rebecca

[Don Coatney]

I have not yet installed the new thermostat. Others here have done so with success. The new thermostat is a 3 piece deal. There is a rubber gasket that seals the top of the thermostat to the housing. The by-pass flow follows the pipe cleaner I have inserted for this picture. Drilling of additional holes is not required.

[n1gzd_plymouth]

sounds good. I can see that you don't need to drill a hole.

Thanks for the pics.

Rebecca

[Young Ed]

I've got the thermostat Don mentions in my car. 8K miles with no issues. Its also the same as the one I removed. So apparently they've been around awhile. I did switch mine to a 160 degree thermostat though.

[n1gzd_plymouth]

I've got the thermostat Don mentions in my car. 8K miles with no issues. Its also the same as the one I removed. So apparently they've been around awhile. I did switch mine to a 160 degree thermostat though.

I don't remember what I bought. I hope it is 160 deg. I don't have heat, I would rather have it run cooler.

Rebecca

[Jim Saraceno]

The mongrel under my hood has a '57 block with an internal bypass water pump. It also had the external bypass thermostat housing with a standard thermostat installed. Looks similar to this:

Anyway, my engine was running a little on the warm side (usually highway speeds on a warm day). I thought I may be having a problem from both bypasses bypassing too much water so I plugged the external bypass so it uses the internal bypass only.

It seems to run cooler now.